Loud-speaking device



L. DE FOREST LOUD SPEAKING DEVICE F1106 Oct. 28, 1922 a SAL 0L: INVENTOR 5 \1 BY ATTORNEYS W citizen of the Pa t ented Sept. 22, 1925.

uNiT osTA-riis 1,554,194 PATENT" OFFICE.

, LEE pi FOREST, OF NEW YORK, N. Y., ASSIGNOR, BY HESNE ASSIGNMENTS, TO DE FOB.-

EST YHONOEILM CORPORATION, OF JERSEY OI DELAWARE.

7 Application filed October as, 1922. Serial n 597,514.

To all whom it may conoem Be it kno u that I, LEE nn FOREST, 2. nited States, residing at New York, county and State of New York, have made a certain new and useful Invention in Loud-Speaking Devices, of which the following is a specification. p

-.This invention relates to loud speaking devices.

; reference character wherever 40 An object of the invention is to provide a device of this nature which is simple in construction, economical of manufacture and efficient in operation. 4 A further object of the invention is to provide a loud speaker of this type wherein the ordinary telephone receiver may be employed for thepurpose of effecting the amplified or loud reproduction of the electrical variations in telephone receivers.

Further objects of the invention will appear more fully hereinafter. I

.The invention consists substantially in the construction, combination, location and relative arrangement of parts, all as will be more fully hereinafter set forth as shown by the accompanying jdrawing and finally pointed out in the appended claims.

Referring to the drawing:

Figure lis a view in side elevation of the loud speaker construction embodying my invention, the same being shown in longitudinal section.

Fig. 2 is a similar view of a slightly modified construction embodying my invention.

Fig. 3 is a sectional view taken on the lines 33 of Fig. 2, looking in the direction of the arrow.

The same part is designated by the same it occurs throughout the several views.

There are known to the art loud speaking devices in which the sound is led from its source into a second horn or cone of slightly stretched paper, thin leather or other nonmetallic material, for transmitting sound waves. Such horns are being used, for instance, in connection with phonographs in which the phonograph needle is located at the apex of the cone.

It is amongthe special purposes of my present invention to provide a loud speaking device which utilizes this type of diaphragm or cone but which operates on a dif-' ferent principle and. the efore is. made avail-- LOUD-SPEAKING .nnvIoE.

CITY, NEW JERSEY, A CORPORATION able for use .in connection with electrical sound-receiving apparatus, such as a telephone receiver, an 'thus provide a device which is adaptable for the reception of all electrical communications such as radio communications or the like.

spider 1 preferably with a comparatively heavy rim, between parts of which is clamped a non-metallic diaphragm 2, such as parchment, paper, thin leather, or the like. This parchment is stretched, preferably in the shape of a cone, but I-do not desire to be restricted or limited in this respect. The diaphragm may be maintained in taut position in any suitable manner, for example, by means of a rod 3 terminating at one end in a spider 14 which supports a ring 15' secured thereto, said ring to engage the diaphragm preferably one-half or one-third of the distance from the apex of the cone to the periphery. The rod '3 is provided with screw threads 5 at the opposite end thereof which engage a nut 6 positioned inside of the hub of the spider 1.

It will thus be seen that by varying the position of the nut which is on the threaded portion 5 of the rod 3, the tension imparted to the diaphragm 2 may be varied, thus permitting an easy manner of maintaining the diaphragm taut under all conditions of temperature or atmospheric conditions.

. j i In accordance with my invention I employ a cone structure cons1sting essentially oiva The apex of the conical diaphragm is provided with a needle point 7 projecting through the diaphragm 2 and this needle point is placed in contact with the diaphragm of an ordinary telephone receiver. Thus it will be seen that the vibrations imparted to the diaphragm of the ordinary telephone receiver 8 are imparted directly to the diaphragm 2, and thus the sound in a greatly amplified condition is reproduced in an undistorted non-metallic manner, the

by means of the brackets, a s diagrammatically illustrated. In this instance the rod 3, remote from the apex of the cone, 1S placedin needle contact with the diaphragm of the tele hone receiver 8, and the rod 3 is maintained taut by means of a suitable spring. 9 secured at one end to the rod 3, and at the other end to. the supportlng wall or structure 10.

For the purpose of providing a simple and eflicient sup rting structure for the loud speaking device of my invention, I have shown an arrangement in Fig. 1 whereln the device is attached to any su1table supporting body, such as a wooden strip 1llustrated at 10. This base 10 is provided with a suitable bracket 11 for supporting the telephone receiver. Rigidly secured to the wooden base stri is an arm 12, the end of which is pivotal y clamped in an su table manner to.the lower ortion of t e r1m"1. A. spring 13 is detac abl secured atone end to the upper portion 0 the nm 1, and at the other end permanently aflixed to the base strip 10 as shown. The function of the spring 13 is to maintain the arm 3 1n firm contact with the diaphragm of the telephone receiver 8. I have found that if the wooden base 10 be made art of, or attached directly to, one si e of a hollow sound-resonant chamber 'or box having one side open, or'having suitable a rtures cut into one of its sides, e. g., a violin r violincello body, then the acoustic efiect roduced by the vibration of the conical diaphragm is greatly enhanced. prefer, therefore, to employ the arrangement herein described mounted 'upon such hollow resonant chamber, as shown at 20.

Many modifications and chan es in detail will readily occur to those ski led in the art without departing from the spirit and scope of my invention, but having now set forth the objects and nature of my invention, and having shown and described a construction embodying the principles therein, what I claim as new and useful and of my own invention, and desire to secure by Letters Patent is:

1. A loud speaking device, comprising in combination with a telephone receiver of the diaphragm type,a substantially cone-shaped y of non-metallic material, and means for vibrating said body by and in accordance with the vibrations of the diaphragm ofsaid telephone receiver.

2. A loud speaking device, comprisin in combination with a telephone receiver 0 the diaphragm type, a'substantially cone-shaped b0 y of non-metallic material, and a rigid member extending from the apex of said body and contacting with the surface of the diaphragm of said telephone receiver.

3 A oud speaking device, comprising in combination with a tale hone recelver of the diaphragm type, a su stantially coneshaped body of non-metallic material, means for adjustably mainta-inin said bodyin a taut condition, and means or vibrating said body by and in accordance with the vibrations of the diaphragm of said telephone receiver.

4. A loud speaking device, comprising in combination with a telephone receiver of the diaphragm type, a substantially coneshaped body of non-metallic material, means for adjustably maintaining said body in a taut condition, said'means including means for vibrating said body by and in accordance with the vibrations of the diaphragm of said telephone receiver.

5. In a loud speaking device, a case, a telephone receiver supported therein, a substantially cone-shaped body of non-metallic material provided with a substantially rigid extension from the apex thereof, and means for supporting said body in said case so that the end of said extension is in'contact with the surface of the diaphragm of said telephone receiver.

6, In a loud speaking device, a case, a'

telephone receiver supported therein, a substantially cone-shaped body of non-metallic material provided with a substantially rigid extension from the apex thereof, and means for detachably supporting said bodyim'said case so that the end of said extensiomis in contact with the surface of the diaphragmof said telephone receiver.

7. In a loud speaking device, a case, a telephone receiver supported therein, a substantially cone-shaped body of non-metallic material provided with a pin attached to the apex thereof, and means for supporting said body so that the end of .said extension is in contact with the surface of the diaphragm of said telephone receiver.

In testimony whereof I have hereunto set my .hand on this 15th day of October A. 1)., 1922.

LEE DE FOREST. 

